WO2007119422A1

WO2007119422A1 - Information communication system, information communication method, node device contained in information communication system, and recording medium containing information processing program

Info

Publication number: WO2007119422A1
Application number: PCT/JP2007/055516
Authority: WO
Inventors: Hideki Matsuo
Original assignee: Brother Kogyo Kabushiki Kaisha
Priority date: 2006-04-13
Filing date: 2007-03-19
Publication date: 2007-10-25
Also published as: JP4539603B2; US8218455B2; US20090003244A1; JP2007288307A

Abstract

It is possible to provide an information communication system and others in which a participation requesting node can acquire link information (IP address and the like) on the node device participating in an overlay network. The information communication system includes an overlay network formed by participation of a plurality of node devices. One node device (B) contained in the system stores node information indicating a node device as a candidate of an information transfer destination. When the node device (B) receives a participation message indicating a request for participating in the overlay network from a participation requesting node (Z), the node device (B) transfers the participation message to the node device (E) of the transfer destination in accordance with the node information on the participation requesting node (Z) and transmits an existence confirmation message including the node information on the participation requesting node to node devices (A, C) other than the transfer destination based on the node information on the participation requesting node (Z). Upon reception of the existence confirmation message, a response message is transmitted to the participation requesting node.

Description

Specification

Information communication system, information communication method, node device included in information communication system, and recording medium on which information processing program is recorded

Technical field

TECHNICAL FIELD [0001] The present invention relates to a technical field such as a Peer to Peer (P2P) type information communication system and method including a plurality of node devices connected to each other via a network.

Background art

In recent years, peer-to-peer technology has attracted attention. In a peer-to-peer type information communication system, for example, in an overlay network logically constructed using a distributed hash table (hereinafter referred to as DHT (Distributed Hash Table)), each node device is connected to the overlay network. Retains only link information to some node devices that is obtained when joining, such as when it does not recognize link information (for example, IP address) to all participating node devices. Data), and it is now possible to query and match data based on strong link information.

[0003] In such an overlay network, even when node devices frequently participate and leave (leave), load balancing must be performed appropriately. Even when participation and withdrawal (withdrawal) are frequently performed, techniques for appropriately distributing loads are disclosed.

Non-Patent Document 1: Toshio Oka, Hiroyuki Morikawa, Yuki Aoyama, “Examination of lightweight load distribution method for distributed hash table”, IEICE technical report, (Japan), IEICE, 2004 2 5th, No. 103, No. 650, p.7-12

Disclosure of the invention

Problems to be solved by the invention

[0004] When a node device newly participates in the overlay network, it transmits a participation request message to a contact node that recognizes V in advance. The contact node and other node devices operate as follows, so that the node device that sent the participation request message ( Hereinafter, it is called a participation request node. ) Is a way to acquire link information of other node devices and create a routing table for DHT.

[0005] Upon receiving the participation request node force participation request message, the contact node returns link information of the other node devices registered in the largest stage of the DHT routing table. In addition, the contact node is not required to send a participation request message unless the own node device is the root node of the participation request node (the unique identification information (node ID) corresponding to the link information is the closest to the participation request node). To the node device. When the contact node forwards the participation request message, it sends the information of the next stage that returns link information to the participation request node.

[0006] The node device that has received the participation request message transferred in this way transmits the link information of the corresponding node device to the participation request node based on the information at the stage of returning the link information. Also, this node device forwards the participation request message to another node device if the node device is not the root node of the participation request node. The power of the node device to which the participation request message has been transferred Further, when transferring the participation request message, the link information is returned to the participation request node, and further information on the next stage is transmitted.

[0007] In this way, the participation request message is transferred to the root node of the participation request node, and each node device that has received the participation request message returns link information at a predetermined stage to the participation request node.

[0008] A participation request node that receives link information one after another creates a DHT routing table based on the link information.

[0009] However, when the participation request node creates the routing table in the above procedure, the information of the node device that has already left the overlay network power is included in the received link information of the other node devices. May be included. Then, when information is sent to the node device that has withdrawn or the node device that has a near-node ID, the information transfer may be delayed.

Therefore, the present invention has been made in view of the above inconvenience, and participates in a peer-to-peer information communication system and method including a plurality of node devices connected to each other via a communication path. Requesting node is participating in the overlay network It is an object of the present invention to provide an information communication system and method capable of acquiring only link information of a node device.

Means for solving the problem

In order to solve the above-mentioned problem, the invention according to claim 1 is an information communication system having an overlay network formed by participation of a plurality of node devices connected to each other via a communication path. One node device included in the plurality of node devices indicates a storage means for storing node information indicating a node device that is a candidate for an information transfer destination, a request to participate in the overlay network, and When receiving participation request information including node information of a participation request node device that requests participation, the ability to store node information indicating a transfer destination node device according to the node information of the participation request node device If the node information indicating the transfer destination node device is stored, the participation request information transfer for transferring the participation request information to the node device. And whether or not node information indicating a node device other than the transfer destination corresponding to the node information of the participation request node device that is the transmission source of the participation request information is stored when the participation request information is received. And storing node information indicating a node device other than the transfer destination, and transmitting presence confirmation information including the node information of the participation request node device to the node device. And a reply information transmitting means for transmitting reply information to the participation request node device when the presence confirmation information is received.

[0012] According to this, the presence confirmation information transmitting unit of the node device that has received the participation request information transmits the presence confirmation information to another node device, and the reply information transmitting unit of the node device that has received the presence confirmation information In order to send reply information to the participation request node device (hereinafter also simply referred to as participation request node), the participation request node confirms that the node device that sent the reply information participates in the overlay network. it can. Therefore, a participation request node newly participating in the overlay network can acquire node information (for example, an IP address, etc.) that becomes link information of a node device that is surely participating in the overlay network. The participation request node can store each node information in the storage means based on the acquired node information and the like. [0013] It should be noted that the node device that is the source of the presence confirmation information can confirm that the other node device exists, if the presence confirmation information can be transmitted to the other node device. If it is impossible to send the presence confirmation information, it can be confirmed that the other node device is present, and it is possible to confirm that the other node device is present.

[0014] In order to solve the above problems, the invention according to claim 2 is an information communication system having an overlay network formed by participation of a plurality of node devices connected to each other via a communication path. In the communication method, one node device included in the plurality of node devices stores a node information indicating a node device that is a candidate for an information transfer destination, and indicates a request to participate in the overlay network. And when receiving participation request information including node information of a participation request node device that requests participation, node information indicating a transfer destination node device according to the node information of the participation request node device is stored. A step of determining whether or not the power is received, storing node information indicating the node device of the transfer destination, and transferring the participation request information to the node device in this case When the participation request information is received, the node information indicating the node device indicating the node device other than the transfer destination according to the node information of the participation request node device that is the transmission source of the participation request information is stored. Storing node information indicating a node device other than the transfer destination, and transmitting presence confirmation information including the node information of the participation request node device to the node device, And a step of transmitting return information to the participation requesting node device when presence confirmation information is received.

In order to solve the above-mentioned problem, the invention according to claim 3 is an information communication system having an overlay network formed by participation of a plurality of node devices connected to each other via a communication path. A storage means for storing node information indicating a node apparatus that is a candidate for an information transfer destination, and a participation request node that indicates and requests participation in the overlay network. When participation request information including node information of a device is received, node information indicating a transfer destination node device corresponding to the node information of the participation request node device is stored! If the node information indicating the node device of the transfer destination is stored, participation request information transfer means for transferring the participation request information to the node device, and the participation request information Is received, Whether node information indicating a node device other than the transfer destination according to the node information of the participation request node device that is the transmission source of the participation request information is stored! If the node information indicating the node device is stored, the presence confirmation information transmitting means for transmitting the presence confirmation information including the node information of the participation request node device to the node device, and the presence confirmation information are received. In this case, the node device further comprises a reply information transmitting means for transmitting reply information to the participation request node device.

[0016] According to this, since the node device has each of such means, the participation request node that newly joined the overlay network is the node device that is surely participating in the overlay network. Link information can be acquired.

[0017] In order to solve the above-described problem, the invention according to claim 4 is a node device that has received the reply information from the node device according to claim 3, and is a transmission source of the received reply information. A node device characterized by comprising storage means for storing the node information corresponding to the node device.

[0018] According to this, the participation request node can store node information of other node devices that are surely participating in the overlay network at that time based on the received reply information. Therefore, processing such as information transfer in the information communication system proceeds without delay, and the communication efficiency of the entire information communication system is improved.

[0019] In order to solve the above-described problem, the invention according to claim 5 is the node device according to claim 3, wherein the storage means includes the node information and a unique information corresponding to the node information. The identification information is stored in association with each area of the identification information, and the participation request information transfer means specifies the predetermined area in the storage means when transferring the participation request information. Information is added to the participation request information, and the presence confirmation information sending means adds the area designation information to the received participation request information, and the contents of the area designation information. Accordingly, the node device is characterized in that when the node information of another node device as a transmission destination is stored, the existence confirmation information is transmitted to the node device.

[0020] According to this, the node device attaches the area designation information when transferring the participation request information, so that other information belonging to each area of the identification information suitable for the identification information of the participation request node can be obtained. Existence confirmation information can be transmitted to the node device. Then, since the node device that has received the presence confirmation information transmits the return information to the participation request node, the participation request node includes the node information of the node device belonging to each area of the identification information suitable for the identification information of the participation request node. The node information of each node device can be stored in a well-balanced manner. As the participation request node stores the node information of other node devices in this way, processing such as information transfer in the information communication system proceeds without delay, and the communication efficiency of the entire information communication system is further improved.

[0021] In order to solve the above problem, the invention according to claim 6 is the node device according to claim 5, wherein the area of the identification information is divided into a plurality of areas according to the rules of the identification information. The region to which the own node device belongs is further divided into a plurality of regions according to the rules of the identification information until the region to which only the own node device belongs is present. If the area designation information is added to the received participation request information, the presence confirmation information is stored in another node apparatus belonging to the area corresponding to the area designation information of the identification information. When the region designation information is added to the received participation request information, the participation request information transfer means transmits the participation request information to a range smaller than the region of the identification information corresponding to the region designation information. The node device characterized in that the region designation information designating a corresponding region is added to the participation request information.

[0022] According to this, the area of the identification information is divided as described above, and by adding the area specifying information as described above, the participation request node can identify the identification suitable for the identification information of the participation request node. Node information of node devices belonging to each area of information can be acquired, and node information of each node device can be stored in a balanced manner. Such a configuration can be applied to, for example, a routing table using DHT, and can smoothly perform routing processing used for information transfer in the information communication system. Communication efficiency is further improved.

[0023] In order to solve the above-mentioned problem, the invention according to claim 7 is the node device according to any one of claims 3, 5 or 6, wherein the presence confirmation information transmitting means When the presence confirmation information is transmitted, the node of the node device to which the presence confirmation information is transmitted A node device further comprising node information transmitting means for transmitting information to the participation requesting node device.

[0024] According to this, the node device having the presence confirmation information transmitting means functioning transmits the node information of the node device that is the transmission destination of the presence confirmation information to the participation request node, so that the node device A part of the stored node information is transmitted to the participation request node. The participation request node receives part of the node information stored in the other node device, and also receives reply information from the node device corresponding to the node information, so that it can participate in the overlay network more accurately. The node information of the node device that is in operation can be stored.

[0025] In order to solve the above problem, the invention according to claim 8 is such that an information processing program for causing a computer to function as the node device according to any one of claims 3 to 7 is readable by a computer. The recording medium is characterized by being recorded.

The invention's effect

[0026] According to the present invention, the node device newly participates in the overlay network by having each of the above means, particularly the participation request information transfer means, the presence confirmation information transmission means, and the reply information transmission means. The participation request node can participate in the overlay network and acquire the link information of the node device.

Brief Description of Drawings

FIG. 1 is a diagram showing an example of a connection mode of each node device in the information communication system according to the present embodiment.

FIG. 2 is a diagram showing an example of how an ID space and a routing table are created by DHT.

FIG. 3 (A) is an example of a level 1 table. (B) An example of a level 2 table. (C) An example of a level 3 table. (D) An example of a completed routing table.

FIG. 4 is a diagram showing a schematic configuration example of a node device 1.

FIG. 5 is a diagram for explaining a mode in which a DHT routing table is created after node device 1 joins an overlay network. [FIG. 6] (A) to (C) are diagrams each showing a DHT routing table stored in another node device 1.

[FIG. 7] A diagram showing a DHT routing table created by node Z, which is a participation request node.

FIG. 8 is a flowchart showing basic processing in the node device 1.

FIG. 9 is a flowchart showing message reception processing in the node device 1.

FIG. 10 is a flowchart showing registration processing in a table of another node device 1 in the node device 1.

Explanation of symbols

1 node device

8 network

9 Overlay network

11 Control unit

12 L | S B '| 5

13 Noffa memory

14 Decoder part

15 Video processor

16 Display

17 Audio processor

18 Speaker

20 Communications department

21 Input section

22 Nos

s Information communication system

BEST MODE FOR CARRYING OUT THE INVENTION

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described with reference to the drawings. The embodiment described below is an embodiment in which the present invention is applied to an information communication system using a DHT, an IP address as node information, and a node ID as identification information. In this embodiment In the above information communication system, a node device (participation request node) newly participating in the overlay network transmits a participation message as participation request information to a contact node which is an arbitrary node device, as presence confirmation information. The participation request node creates a DHT routing table using the existence confirmation message and response message as the return information. Note that the invention of the information communication system and the like of the present invention is not limited to the embodiments described below, and is appropriately modified and implemented within the scope of the technical idea of the present invention.

[1. Configuration of information communication system]

First, a schematic configuration of the information communication system will be described with reference to FIG.

FIG. 1 is a diagram illustrating an example of a connection mode of each node device in the information communication system according to the present embodiment.

[0032] As shown in the lower frame 101 of FIG. 1, IX (Internet eXchange) 3, ISP (Internet Service

Provider) 4, DSL (Digital Subscriber Line) line provider (equipment) 5, FTTH (Fiber To The Home) line provider (equipment) 6, and communication line (for example, telephone line or optical cable) A network such as the Internet (real-world network) 8 is constructed by 7 etc.

[0033] The information communication system S includes a plurality of node devices la, lb, lc---lx, ly, 1ζ ··· that are connected to each other via such a network 8. This is a peer-to-peer network system. Each node device la, lb, lc---lx, ly, 1ζ · · · is assigned a unique serial number and IP (Internet Protocol) address as information indicating the node device (node information in the present invention). Yes. The serial number and IP address do not overlap among the plurality of node devices 1. In the following description, when any one of the node devices la, lb, lc---lx, ly, 1ζ ... is indicated, it may be referred to as node device 1 for convenience. .

[0034] [1. 1. Overview of DHT]

The algorithm using the distributed hash table (hereinafter referred to as DHT (Distributed Hash Table) t \) according to the present embodiment will be described below.

[0035] In the information communication system S described above, when the node devices 1 exchange information with each other, the IP addresses as the node information of each other must be known. Yes.

[0036] For example, in a system that shares content with each other, it is simple for each node device 1 participating in the network 8 to know the IP addresses of all the node devices 1 participating in the network 8. If the number of terminals is tens of thousands and hundreds of thousands, it is not realistic to remember the IP addresses of all the node devices 1. If the power of any node device is turned ON or OFF, the IP address of the arbitrary node device stored in each node device 1 is frequently updated, which makes operation difficult.

[0037] Therefore, in one node device 1, only the minimum necessary IP address of the node device 1 among all the node devices 1 participating in the network 8 is memorized (stored). Do not know the IP address! /, (Remember me! /, Na! /,) For node device 1! / For each node device 1, transfer information to each other and send it to each other. When you get it, the cocoon system is devised.

As an example of such a system, an overlay network 9 as shown in an upper frame 100 of FIG. 1 is constructed by an algorithm using DHT. In other words, this overlay network 9 means a network that forms a virtual link formed using the existing network 8.

[0039] In the present embodiment, an overlay network 9 constructed by an algorithm using DHT is assumed, and the node device 1 arranged on the overlay network 9 participates in the information communication system S (in other words, in other words). For example, node device 1 participating in overlay network 9). In addition, participation in the information communication system S is still participating and participating in any node device 1 (hereinafter also referred to as a contact node) that has already participated and participated in any node device 1 (hereinafter also referred to as a contact node). This is done by sending request information (hereinafter also referred to as a participation message). The participation message as participation request information indicates a request for participation in the overlay network and includes node information of the participation request node that requests participation.

[0040] The node ID (identification information) of each node device 1 that participates in the information communication system S is assigned a unique number for each node device. This number must have enough bits to accommodate the maximum number of node devices. For example, if a 128-bit number is used, it is possible to operate 2 "128 = 340 X 10" 36 node devices. More specifically, the node ID of each node device 1 is hashed with a common hash function (hash algorithm), which is a unique value for each node device, such as the IP address or serial number of each node device. The hash value obtained in this way is distributed evenly in one ID space. In this way, the node ID (hashed) obtained by a common hash function has a very low probability of having the same value if the IP address or serial number is different. Since the hash function is publicly known, detailed explanation is omitted. In this embodiment, a value obtained by hashing an IP address (global IP address; node information) with a common hash function is used as a node ID (GUID (Global Unique IDentifier); identification information).

[0042] [1. 2. Create Routing Table]

With reference to Fig. 2, an example of the creation method of the routing table used in DHT will be explained. Figure 2 shows an example of how the routing table is created by the DHT.

[0043] Since the node IDs assigned to the respective node devices 1 are generated by a common hash function, the node IDs are slightly biased on the same ring-shaped ID space as shown in FIG. 2 (A) to FIG. 2 (C). Rather, it can be thought of as being scattered. The figure shows a node ID assigned with 8 bits. Black dots in the figure indicate node IDs, and IDs increase counterclockwise.

First, the ID space as shown in FIG. 2 (A) is divided into several areas. Actually, about 16 divisions are often used, but in order to simplify the explanation, it is assumed here that the division is 4 and the ID is expressed as a quaternary number with a bit length of 8 bits. An example in which the node ID of the node device 1N is “1023” and the routing table of the node device 1N is created will be described.

[0045] (Level 1 routing)

First, if the ID space is divided into four parts, each area is expressed in quaternary numbers with different maximum digits. Four areas “0XXX”, “1XXX”, “2XXX”, “3XXX” (X is an integer from 0 to 3, Same as). Since the node ID of the node device 1N itself is “1023”, the node device 1N exists in the lower left “1XXX” area in the figure. Then, the node device 1N is a node device that exists in an area other than its own area (ie, the “1XXX” area). Select device 1 as appropriate and store the IP address of the node ID in the level 1 table. Figure 3 (A) shows an example of a level 1 table. The second column indicates the node device 1N itself, so there is no need to store the IP address.

[0046] (Level 2 routing)

Next, among the areas divided into four by the above routing as shown in Fig. 2 (B), the area where I exist is further divided into four, and further four areas "10XX" "11XX", "12XX", "13X" X ". Then, similarly to the above, the node device 1 existing in an area other than the area where the user exists is appropriately selected, and the IP address of the node ID is stored in the level 2 table. Figure 3 (B) is an example of a level 2 table. The first column shows the node device 1N itself, so there is no need to store the IP address.

[0047] (Level 3 routing)

Furthermore, among the areas divided into four by the above routing as shown in FIG. 2 (C), the area where it exists is further divided into four, and further four areas “100X” “101X” “102X” “103” X ". Then, similarly to the above, the node device 1 existing in an area other than the area where the user exists is appropriately selected, and the IP address of the node ID is stored in the level 1 table. Figure 3 (C) shows an example of a level 3 table. The third column shows the node device 1N itself, so there is no need to store the IP address. The second column and the fourth column are blank because there is no node device in the area.

[0048] By creating the routing table in the same manner up to level 4 as shown in Fig. 3 (D) in this way, all 8-bit IDs can be covered. As the level goes up, white space becomes more noticeable in the table.

[0049] All the node devices 1 create and own the routing table created according to the method described above. In this way, the node device 1 creates a DHT routing table that stores the IP addresses of the other node devices 1. In this embodiment, the node device 1 has an IP address as node information, a node ID as identification information, and an area of a node ID space as an area to which identification information belongs, that is, each level of DHT. And each column is stored in association with each other. Here, the node device corresponding to the node ID closest to the node ID of its own node device 1N is assigned to the root node (Fig. 2 (C) and Fig. 3 (D) described later). Oh! In the end, it is assumed that the node device has a node ID of 1000).

[0050] Note that the number of levels is determined according to the number of digits of the node ID, and the number of attention digits of each level in FIG. 3 (D) is determined according to the number of decimal numbers. Specifically, if it is a 16-digit hexadecimal number, it will be a 6-bit ID, and at level 16, the (alphabetic) digits of interest will be 0 to f. In the description of the routing table described later, the portion indicating the number of digits of interest at each level is simply referred to as “column” or “number of columns”.

[0051] [2. Configuration of node device, etc.]

Next, the configuration and function of the node device 1 will be described with reference to FIG. The configuration of each node device 1 is the same. FIG. 4 is a diagram illustrating a schematic configuration example of the node device 1.

As shown in FIG. 4, each node device 1 includes a CPU 11 having a calculation function, a working RAM, a ROM that stores various data and programs, a control unit 11 as a computer, content data, HD power for storing (storing) index information, DHT and programs, etc. Storage unit 12 as configured storage means (the above content data may be stored on node device 1) and received Buffer memory 13 that temporarily stores the content data that has been encoded, and a decoder that decodes the encoded video data (video information), audio data (audio information), etc. included in the content data (data expansion, decoding, etc.) Unit 14, a video processing unit 15 that performs a predetermined drawing process on the decoded video data and the like, and outputs the result as a video signal. Display unit 16 such as a CRT or liquid crystal display that displays video based on the video signal output from the video processing unit 15, and D (Digital) / A (Analog) conversion of the decoded audio data into an analog audio signal Information between the audio processing unit 17 that amplifies this with an amplifier and outputs it, the power 18 that outputs the audio signal output from the audio processing unit 17 as a sound wave, and the other node device 1 through the network 8 A communication unit 20 for performing communication control, and an input unit (for example, a keyboard, a mouse, or an operation panel) that receives an instruction from the user and provides an instruction signal corresponding to the instruction to the control unit 11. The control unit 11, the storage unit 12, the buffer memory 13, the decoder unit 14, and the communication unit 20 are connected to each other via a bus 22.

[0053] Then, the CPU in the control unit 11 executes various programs stored in the storage unit 12 or the like. As a result, the entire node device 1 is controlled in an integrated manner, and content data registration processing and the like are performed in accordance with an instruction signal from the input unit 21. The node device 1 functions as a node device that transmits (transfers) information, a node device that receives information, and the like according to a program to be executed. In addition, the control unit 11 of the node device 1 functions as a participation request information transfer unit, a presence confirmation information transmission unit, a reply information transmission unit, and a node information transmission unit of the present invention.

[3. Outline of Information Communication System]

An outline of the information communication system S of the present embodiment will be described with reference to FIGS. The information communication system S according to the present embodiment receives a response message as reply information of another node device after one node device participates in the overlay network, thereby receiving the node device that is the transmission source of the response message. DHT routing table is created based on the information of. In the following description, the node that requests participation is assumed to be node Z, and any node device that already knows the IP address (hereinafter referred to as a contact node) that communicates for the first time at node Z power is called node B. To do.

[0055] In the following, the DHT routing table is also simply referred to as a table. Also, the word “registration” is used to store node information and identification information of other node devices.

[0056] FIG. 5 is a schematic diagram showing the flow of each message for creating a DHT routing table after the participation request node has entered the information communication system S. Each figure in FIG. Fig. 7 is an example of a DHT routing table that has already been stored in Node B, Node Έ, and Node G that have already participated in the information communication system S, and Fig. 7 shows that node Z returns reply information (response message). It is an example of the DHT routing table created by receiving.

[0057] As shown in FIG. 5, when one node device 1 (node Z) participates in the communication network in the information communication system S, the node Z participates in node B, which is a contact node, as participation request information. Send the message (arrow 101). Then, node A confirms that node B exists by successfully transmitting the join message (arrow 102). Next, node B sequentially transmits an existence confirmation message as existence confirmation information to node A, node E, and node C registered at level 1 as shown in FIG. 6 (A) (arrow 103, 105, 1 07). Node A then sends a response message to node Z (arrow 104), node E sends a response message to node Z (arrow 106), and node C sends a response message to node Z (arrow 108). ). In Fig. 6 (A) to Fig. 6 (C), if there is a ▲ mark to the left of the number of levels, it means that an existence confirmation message is sent to the node device registered at that level. A node device surrounded by a double square means that a participation message is transferred to the node device.

At this time, node Z obtains the IP addresses of node A, node B, node C, and node E in the table of FIG. 7, and associates the IP address with the corresponding node ID to obtain the SD address. .

[0059] Node B then forwards the join message to the root node of node Z, here node E (arrow 109). At this time, region designation information indicating that the destination of the existence confirmation message is the next level 2 is added to the participation message. Next, as shown in FIG. 6 (B), node E sequentially transmits a presence confirmation message to node G, node D, and node F registered in the next level 2 (arrows 110, 112, 114). ). Node G then sends a response message to node Z (arrow 111), node D sends a response message to node Z (arrow 113), and node F sends a response message to node Z (arrow 115). ).

[0060] At this time, the node Z can store the IP addresses and node IDs of the nodes D, F, and G in the table of FIG.

[0061] Node E then forwards the join message to the root node of node Z, here to node G (arrow 116). At this time, area designation information indicating that the destination of the existence confirmation message is the next level 3 is added to the participation message. Next, as shown in FIG. 6C, the node G transmits a presence confirmation message to the node H registered at the next level 3 (arrow 117). Node Ή then sends a response message to node Z (arrow 118). Here, since node G is the root node of node Z and there is no further transfer destination, the processing is terminated.

At this time, the node Z can store the IP address and node ID of the node H in the table of FIG. 7, and the node Z can create the DHT routing table shown in FIG. 7 by the above flow. This node Z table is received from each existing node device 1. Since it was created based on the received response message, the other node device 1 stored in the table has left, so there is a probability that transmission or transmission of information based on the table will be delayed. Lower. Accordingly, the communication efficiency of the information communication system S as a whole is improved.

[0063] [3. Operation of Information Communication System of this Embodiment]

Next, the operation of each node device 1 in the information communication system S of the present embodiment will be described using FIG. 5 to FIG. Processing in each node device 1 after one node device 1 (the node Z described above) participates in the communication network in the information communication system S will be described with reference to the flowcharts in FIGS. Each process will be described by taking several node devices 1 as an example, but every node device 1 performs the same process.

[0064] (1) Basic processing of node device

The basic process of the node device 1 (node Z) will be described with reference to FIG. Note that Node Z, after participating in the communication network, creates and holds (stores) the DHT routing table shown in FIG. 7 according to the procedure shown in FIG.

When the control unit 11 of the node Z recognizes that the power of the node device is turned on by the input unit 11 or the like, various settings of the node Z are initialized and basic processing is started (start). Note that it is assumed that node Z holds the IP address of contact node device 1 (node B) that communicates first when it joins the communication network.

[0066] When the basic processing is started, the control unit 11 transmits a participation message specifying level 1 as region specification information to the contact node (node B) (step Sl). Note that the control unit 11 of the node Z confirms that the contact node B exists when communication with the contact node B is established in order to transmit the participation message, and the control is performed in step S32 of FIG. 10 described later. Thus, the information of node B can be registered in the table. Next, the control unit 11 determines whether or not the power is turned off (step S2), and usually determines that the power is not turned off because the power is not turned off immediately after the power is turned on (step S2). NO), it is determined whether or not a message (information) has been received from another node device 1 (step S3). At this time, since at least the node A force response message is received, it is determined that the other node device 1 (node A) force has also received the message (step S3; YES), and the message receiving process is performed. (Step S4). The message reception process will be described later with reference to FIG.

[0067] Next, the control unit 11 performs registration processing in the table for the node device 1 (node B) that is the transmission source of the received message (step S5). The registration process in this table will be described later with reference to FIG. At this time, the information of node A is registered in the area of attention digit X = 0 of level 1 and each level in the node Z table (see FIG. 7).

[0068] Next, the control unit 11 returns to step S2, and if the power is not turned off (step S2; NO) and no message is received (step S3; NO), the control unit 11 receives the input from the input unit 21 or the like. Perform other processing according to the input (step S6), and return to step S2. Thereafter, the control unit 11 of the node Z repeats the operations of steps S2 to S5 or steps S2, S3, and S6 depending on the case, and when the power of the node Z is turned off, determines so (step S2; YES), the basic processing is ended (END).

[0069] (2) Node device message reception processing

The message reception processing of node Z, node B, node E, node G, and node A will be described with reference to FIG.

[0070] (Node Z)

When the message reception process (step S4) in the above-described basic process starts, the control unit 11 of the node Z starts this message reception process (start). Here, the explanation is based on the assumption that a response message from node A is received.

[0071] When the message reception process is started, the control unit 11 determines whether or not the received message is a participation message (step Sl 1). Here, since the received message is a response message, the control unit 11 determines that the received message is not a participation message (step Sl l; NO), and then determines whether or not the received message is a presence confirmation message. (Step S12).

[0072] Here, since the received message is a response message, the control unit 11 determines that the received message is not an existence confirmation message (step S12; NO), and then the received message is a response message. It is determined whether or not (step S13). Here, the control unit 11 determines that the received message is a response message (step S13; YES ), Return to the original processing flow (return).

[0073] (Node B)

On the other hand, the message reception process when contact node B receives a participation message from node Z participating in the communication network is described below. Node B is assumed to store the table shown in FIG.

The control unit 11 of the node B receives the participation message, and starts the message reception process (start) when the message reception process (step S4) in the basic process described above starts. In step S11, if the control unit 11 of the node B determines that the message is a participation message (step SI 1; YES), area designation information indicating level 1 included in the participation message is acquired. (Step S14). The control unit 11 determines that the number of levels in the table is 1 in accordance with the area designation information of this participation message (step S15).

[0075] Next, the control unit 11 determines that the number of columns in the table (the attention digit X of each level) is 0 (step S16), and the level 1, attention digit X in FIG. Pay attention to the area of = 0.

[0076] Next, the control unit 11 determines whether the determined number of columns is less than or equal to the number of columns in the entire table (step S17), and since the determined number of columns 0 is less than or equal to 3 in the entire table ( Step S1 7; YES), it is determined whether or not the node device corresponding to the noted [number of levels] [number of columns] is its own node device (step S18).

Here, as shown in FIG. 6 (A), since the node device corresponding to [number of levels 1] [number of columns 0] is not its own node device, such a determination is made (step S18; Next, it is determined whether or not the information of other node devices is stored in the noted [number of levels] [number of columns] (step S19).

[0078] Here, since the node device having the node ID [0211] is stored in [number of levels 1] [number of columns 0], the control unit 11 makes such a determination (step S19; YES), and participates in the message. The existence confirmation message including the IP address of node Z that is the transmission source of the node ID is created, and the existence confirmation is made to the node device (node A) of node ID [0211] stored in [number of levels 1] [number of columns 0]. A message is transmitted (step S20). Here, it is assumed that the transmission of the message is successful. Next, the control unit 11 determines whether or not the message transmission process is successful (step S21), and here, since the transmission process of the existence confirmation message is successful, it is determined as such (step S21; YES). Next, the control unit 11 adds 1 to the value of the column number 0 to obtain the column number 1 (step S22), and returns to step S17.

[0080] Next, the control unit 11 is stored in [number of levels 1] [number of columns 1] through step S17; YES, step S18; NO, step S19; YES, step S20, step S21; An existence confirmation message is transmitted to the node device (node E) with the node ID [1221], and 1 is added to the value of the number of columns 1 to set the number of columns 2 (step S23), and the process returns to step S17.

[0081] Next, after step S17; YES, the control unit 11 determines that the area of [number of levels 1] [number of columns 2] is its own node device in step S18 (step S19; YES). Add 1 to the value of Equation 2 to make the number of columns 3 (Step S22), and return to Step S17.

[0082] Next, the control unit 11 stores the [number of levels 1] [number of columns 3] through step S17; YES, step S18; NO, step S19; YES, step S20, step S21; An existence confirmation message is transmitted to the node device (node C) with the node ID [3121], 1 is added to the value of the number of columns 3 to set the number of columns to 4 (step S22), and the process returns to step S17.

Here, the control unit 11 determines whether the determined number of columns is less than or equal to the number of columns in the entire table (step S 17), and the determined number of columns 4 is not less than or equal to 3 in the entire table. (Step S17; NO), the node device of the transfer destination (transmission destination) of the participation message is authorized (Step S23). At this time, since the node device closest to the node ID [101 3] of the node Z that is the participation request node is the node の of the node ID [1221] as described with reference to FIG. Authorize it as the forwarding destination for participating messages.

[0084] Next, the control unit 11 determines whether or not the own node device is the root node, that is, the node device closest to the node ID [1013] of the node Z that is the participation request node (step S24). ). As described above, since the node device closest to the node ID [1013] of the node Z that is the participation request node is the node [of the node ID [1221] and the own node device is not the root node, the control unit 11 makes such a determination (step S24; NO), creates a participation message in which information on the number of levels obtained by adding 1 to the number of levels of interest is added as area specification information, and assigns it to the transfer destination certified in step S24. Transfer (step S25), the original process flow Return (Return). Here, the control unit 11 adds the area designation information of level number 2 to which the number of levels that has been focused on to 1 is added to this to the participation message, forwards it to the node E, and returns to the original flow.

[0085] (Node E)

Next, the message reception process when the node B also receives and receives the participation message at the node Έ is described below. Assume that node E stores the table shown in Fig. 6 (B).

The control unit 11 of the node E receives the participation message, and starts the message reception process (start) when the message reception process (step S4) in the basic process described above starts. In step S11, if it is determined that the message received by the control unit 11 of the node E is a participation message (step SI 1; YES), region designation information indicating level 2 included in the participation message is acquired ( Step S 14). The control unit 11 determines the number of levels in the table as 2 in accordance with the area designation information of this participation message (step S15).

Next, the control unit 11 determines that the number of columns in the table (the attention digit X of each level) is 0 (step S16), and the level 2, attention digit X in FIG. Pay attention to the area of = 0. The control unit 11 determines whether or not the determined number of columns is less than or equal to the number of columns in the entire table (step S17), and since the determined number of columns 0 is less than or equal to 3 in the entire table (step S17; YES ), It is determined whether or not the node device corresponding to the noted [number of levels] [number of columns] is the own node device (step S18).

[0088] Here, as shown in FIG. 6 (B), the node device corresponding to [number of levels 2] [number of columns 0] is not its own node device, so that determination is made (step S18; Next, it is determined whether or not the information of other node devices is stored in the noted [number of levels] [number of columns] (step S19).

[0089] Here, since the node device of node ID [1023] is stored in [number of levels 2] [number of columns 0], it is determined as such (step S19; YES), and the node that is the participation request node A presence confirmation message including the IP address of Z is created, and the message is sent to the node device (node G) of node ID [1023] stored in [number of levels 2] [number of columns 0] (step S20). ). Here, it is assumed that the message transmission process is successful.

Next, the control unit 11 determines whether or not the message transmission process is successful (step S21), and here, since the transmission process of the existence confirmation message is successful, it is determined as such (step S21; YES). Next, the control unit 11 adds 1 to the value of the column number 0 to obtain the column number 1 (step S22), and returns to step S17.

[0091] Next, the control unit 11 is stored in [number of levels 2] [number of columns 1] through step S17; YES, step S18; NO, step S19; YES, step S20, step S21; An existence confirmation message is transmitted to the node device (node D) with the node ID [1120], 1 is added to the value of the number of columns 1 to set the number of columns 2 (step S22), and the process returns to step S17.

[0092] Next, the control unit 11 determines that the area of [number of levels 2] [number of columns 2] is its own node device in step S18 through step S17; YES (step S18; YES) Add 1 to the value of column number 2 to set the number of columns to 3 (step S22), and return to step S17.

[0093] Next, the control unit 11 is stored in [number of levels 2] [number of columns 3] through step S17; YES, step S18; NO, step S19; YES, step S20, step S21; A presence confirmation message is transmitted to the node device (node F) with the node ID [1323], and 1 is added to the value of the number of columns 3 to set the number of columns to 4 (step S22), and the process returns to step S17.

Here, the control unit 11 determines whether or not the determined number of columns is less than or equal to the number of columns in the entire table (step S 17), and because the determined number of columns 4 is not less than or equal to 3 in the entire table. (Step S17; NO), the node device of the transfer destination (transmission destination) of the participation message is authorized (Step S23). At this time, since the node device closest to the node ID [1013] of the node Z that is the participation request node is the node G of the node ID [1023], the node G is recognized as the transfer destination of the participation message.

[0095] Next, the control unit 11 determines whether or not the own node device is the root node, that is, the node device closest to the node ID [1013] of the node Z that is the participation request node (step S24). ). As described above, here, the node device closest to the node ID [1013] of the node Z that is the participation request node is the node G of the node ID [1023], and the own node device is not the root node. Part 11 makes such a determination (step S24; NO), and a participation message in which information on the number of levels obtained by adding 1 to the number of levels of interest is added as area specification information Is created, transferred to another node device authorized as the transfer destination (step S25), and the flow returns to the original processing flow (return). Here, the control unit 11 adds the area designation information of the level number 3 obtained by adding 1 to the level number 3 to the participation message, and sends it to the transfer destination node G for the original processing. Return to the flow.

[0096] Here, when the message transmission process in step S20 is unsuccessful, the control unit 11 determines in step S21 that the message transmission process is not successful (step S2 1; NO), and the corresponding [level [Number] [Number of columns] Information such as IP address of node device 1 is deleted from the tape (step S26), and the process returns to the next step S22.

[0097] (Node G)

Next, in node G, the message reception process when node E is also transferred and received the participation message will be described below. Node G is assumed to have stored the table shown in Fig. 6 (C).

The control unit 11 of the node G receives the participation message, and starts the message reception process (start) when the message reception process (step S4) in the basic process described above starts. If it is determined in step S11 that the message received by the control unit 11 of the node G is a participation message (step SI 1; YES), region designation information indicating level 3 included in the participation message is acquired ( Step S 14). The control unit 11 determines that the number of levels in the table is 3 in accordance with the area designation information of this participation message (step S15).

Next, the control unit 11 determines that the number of columns in the table (the attention digit X of each level) is 0 (step S16), and the level 3, attention digit X in FIG. Pay attention to the area of = 0. The control unit 11 determines whether or not the determined number of columns is less than or equal to the number of columns in the entire table (step S17), and since the determined number of columns 0 is less than or equal to 3 in the entire table (step S17; YES ), It is determined whether or not the node device corresponding to the noted [number of levels] [number of columns] is the own node device (step S18).

[0100] Here, as shown in FIG. 6C, the node device corresponding to [number of levels 3] [number of columns 0] is not its own node device, so that determination is made (step S18; NO), and then determine whether or not it is possible to memorize the information of other node devices stored in the [number of levels] [number of columns] (Step SI 9).

[0101] Here, since no other node device is stored in [Number of levels 3] [Number of columns 0], it is determined as such (step S19; NO), this area is skipped, and the number of columns 0 Add 1 to the value to make the number of columns 1 (step S22), and return to step S17.

[0102] Next, the control unit 11 goes through step S17; YES, step S18; NO, step S19; NO, and no other node device is stored in [number of levels 3] [number of columns 1]. The area is skipped, 1 is added to the value of the number of columns 1, and the number of columns is 2 (step S22), and the process returns to step S17.

[0103] Next, the control unit 11 determines that the area of [number of levels 2] [number of columns 2] is its own node device in step S18 through step S17; YES (step S18; YES) Add 1 to the value of Equation 2 to make the number of columns 3 (Step S22), and return to Step S17.

[0104] Next, the control unit 11 is stored in [number of levels 2] [number of columns 3] through step S17; YES, step S18; NO, step S19; YES, step S20, step S21; An existence confirmation message is transmitted to the node device (node H) with the node ID [1032], and 1 is added to the value of the number of columns 3 to set the number of columns to 4 (step S22), and the process returns to step S17.

Here, the control unit 11 determines whether or not the determined number of columns is less than or equal to the number of columns in the entire table (step S 17), and since the determined number of columns 4 is not less than or equal to 3 in the entire table. (Step S17; NO), the node device of the transfer destination (transmission destination) of the participation message is authorized (Step S23). At this time, since the node device closest to the node ID [1013] of the node Z [1013] that is the participation request node is the own node device (node G) of the node ID [1023], the node G is transferred to the join message. Authorize as a destination.

Next, the control unit 11 determines whether or not the own node device is the root node, that is, the node device closest to the node ID [1013] of the node Z that is the participation request node (step S24). ). As described above, since the own node device (node G) is the root node here, the control unit 11 makes such a determination (step S24; YES) and returns to the original processing flow (return). .

In this way, the transmission process of the existence confirmation message and the transfer process of the participation message for creating the DHT routing table of the node Z that is the participation request node are completed. [0108] (Node A)

On the other hand, the message reception process when node A receives the presence confirmation message in which contact node B force is also transmitted will be described below.

The control unit 11 of the node A receives the presence confirmation message, and starts the message reception process (start) when the message reception process (step S4) in the basic process described above starts. Here, the explanation is based on the assumption that the presence confirmation message from node B has been received.

[0110] When the message reception process is started, the control unit 11 determines whether or not the received message is a participation message (step Sl l). Here, since the received message is an existence confirmation message, the control unit 11 determines that the received message is not a participation message (step Sl l; NO), and then determines whether or not the received message is an existence confirmation message. Is determined (step S12).

[0111] The control unit 11 determines that the received message is a presence confirmation message (step S12; YES), obtains the IP address of the node Z that is the participation request node added to the presence confirmation message, and A response message is transmitted to node Z (step S27), and the process returns to the original processing flow (return).

[0112] In addition, when the message received by the node device 1 is neither the participation message, the existence confirmation message, or the response message, Step Sl 1; NO, Step S12;

NO, step S13: NO is determined and processing is performed when another message is received (step S30), and the flow returns to the original processing flow (return).

[0113] (3) Node device registration processing in a table of other node devices

With reference to FIG. 10 and FIG. 7 described above, registration processing of another node device 1 in the node Z will be described. It is assumed that the node Z has received the response message for the node A force, and the registration process of the other node device 1 will be described.

[0114] When the registration process (step S5) of the other node device 1 in the basic process described above starts, the control unit 11 of the node Z starts the registration process to the node A table (start).

[0115] When the registration process to the table is started, the control unit 11 starts from the received response message. Information of the node A that is the transmission source node device, specifically, information such as an IP address is acquired (step S31). Next, the control unit 11 recognizes and registers an area to be registered in the table from the acquired IP address (step S32), and returns to the original processing flow (return). Since node A has a node ID of 0211 as shown in FIG. 6 (A), the area to be registered in FIG. 7 is level 1 and the attention digit X = 0 of each level. The control unit 11 of the node Z registers the information of the node A in the area of the level 1 and the attention digit X = 0 of each level of the table.

[0116] After that, node Z receives response messages one after another from node E, node C, node G, node D, node F, and node H. Corresponding to these node device power response messages, the information of each node device 1 is registered in the table through steps S31 and S32 described above, and the DHT routing table shown in FIG. 7 is created and stored. In addition, the node Z confirms that the other node device 1 exists when communication with the other node device 1 is established, as in the case where the participation message is transmitted to the node B described above. Information on the other node device 1 can also be registered in the table.

[0117] [4. Variations]

In the above-described embodiment, the storage unit 12 of the node device 1 is configured to be stored in the DHT routing table in association with the IP address and the node ID of the other node device 1, but is not limited thereto. At least node information indicating the node device 1 that is a candidate for the information transfer destination is stored.

[0118] However, the storage unit 12 as the storage means of the node device 1 corresponds to the above node information and unique identification information corresponding to the node information for each region to which the identification information belongs, as in the DHT routing table. It is preferable to store the information. In this case, by using the area designation information described above, the participation request node acquires node information of each node device belonging to each area of identification information suitable for the identification information and stores it in a balanced manner. can do. Furthermore, as in the DHT routing table, the identification information area is divided into multiple areas according to the rules of identification information, and the own node equipment belongs to the stage where only the own node equipment exists. It is preferable that the area is further divided into a plurality of areas according to the rules of identification information. [0119] Here, the node information may include a port number in addition to the IP address, and is not particularly limited. The identification information is not limited to the node ID, and may be other unique identification information corresponding to the node information.

[0120] In the embodiment described above, when the control unit 11 of the node device 1 receives the participation message, the control unit 11 determines whether or not the node device 1 that is the transfer destination is stored and stores it. In this case, the participation message is transferred to the node device 1 (steps S23, S2 4; NO, S25), but is not limited to this. The control unit 11 serving as a participation request information transfer unit of the node device 1 indicates a participation request to the overlay network and receives a participation request information including node information of the participation request node that requests participation. It is determined whether or not the node information indicating the node device of the transfer destination according to the node information of the node is stored. If the node information indicating the node device of the transfer destination is stored, the node device is stored. If you transfer the participation request information to.

In the above-described embodiment, the control unit 11 of the node device 1 is configured to transmit a presence confirmation message to the node device 1 registered at one level in the table (FIGS. 6A to 6). (See the ▲ mark in Figure 6 (C)), but not limited to this. The control unit 11 as means for transmitting presence confirmation information of the node device 1 stores node information indicating a node device other than the transfer destination according to the node information of the participation requesting node device! If the node information indicating the node device other than the transfer destination is stored, a presence confirmation message including the node information of the participation request node is transmitted to the node device. Good. Specifically, the control unit 11 may be configured to transmit an existence confirmation message to the node device 1 registered at a plurality of levels, or to an arbitrarily selected registered node device 1. It is good also as a form which transmits di. Further, the control unit 11 transmits the presence confirmation message to the node device 1 other than the transfer destination described above, and if so, the control unit 11 transmits the presence confirmation message to the node device 1 of the transfer destination according to the node information of the participation request node device 1. You can send.

[0122] In the above-described embodiment, the control unit 11 of the node device 1 transmits the participation message for the first time or when transferring the participation message, the area designation information that is information on the number of levels in the DHT routing table. (Step Sl, S25), but is not limited to this. The control unit 11 as a means for transferring participation request information of the node device 1 The area designation information that can be added to the participation request information by adding the area designation information designating a predetermined area in the storage means when transferring the request information is not limited to the number of levels. In addition, when the area designation information is used, the control unit 11 serving as the presence confirmation information transmission means adds the area designation information to the received participation request information, and responds according to the power of the force and the contents of the area designation information. (Steps S14 and S15) When node information of another node device as a transmission destination is stored, the presence confirmation information is transmitted to the node device.

[0123] Further, as in the above-described embodiment, the control unit 11 as the presence confirmation information transmitting unit stores the area designation information in the received participation request information, if it is stored. It is preferable to transmit the existence confirmation information to other node devices belonging to the area corresponding to the area designation information of the identification information (steps S14, S15, S20). Note that the control unit 11 as the presence confirmation information transmission means stores the area designation information in the received participation request information, such as when the participating node does not use the area designation information. Thus, it is preferable to transmit the presence confirmation information to other node devices belonging to the largest area of identification information (level 1 in the above embodiment) (step S20). At this time, if the area designation information is added to the received participation request information, the control unit 11 as the participation request information transfer means sets the area to be smaller than the area of the identification information corresponding to the area designation information. The area designation information designating the corresponding area is added to the participation request information (steps S14, S15, S25). In addition, the control unit 11 serving as the participation request information transfer means adds the area designation information to the received participation request information, and in this case, the area having the largest identification information (level 1 in the above embodiment). The area designation information designating the area of the next stage (level 2 in the above embodiment) is added to the participation request information (step S25).

The information communication system and the like of the present invention can also perform participation request information transfer processing, presence confirmation information transmission processing, and reply information transmission processing without using the region designation information described above.

In the above-described embodiment, the operation of each node device and the entire system when the node device 1 participates in the information communication system S is not limited to that described with reference to FIGS. The node device 1 having the participation request information transfer means functioned by the operations of S23, S24, and S25 may further transmit the node information of the node device 1 that is the transmission destination of the presence confirmation message to the participation request node. . This operation is a node information transmission means This is performed by the control unit 11. In this case, the participation request node can acquire node information of other node devices from the two node devices, and can record a more accurate DHT routing table.

[0126] In the above-described embodiment, the node A or the like that has received the existence confirmation message transmits a response message to the participation request node (node Z), but is not limited thereto. The control unit 11 serving as a reply information transmitting unit of the node device 1 may transmit the reply information to the participation request node at least when the presence confirmation information is received. For example, the control unit 11 as a reply information transmission unit of the node device 1 may further transmit the reply information to the participation request node when the participation request information is received.

[0127] Further, a program corresponding to each operation of the node device 1 described above is recorded in an information recording medium such as a flexible disk or a hard disk, or is acquired and recorded via a network such as the Internet. In addition, it is possible to make the microcomputer function as the control unit 11 according to each embodiment by reading and executing it by a microcomputer or the like.

[0128] In addition, the entire disclosure of the Japanese patent application (No. 2006—110626), including the specification, claims, drawings, and abstract filed on April 13, 2006, is referred to in its entirety. Incorporated here.

Claims

The scope of the claims

[1] An information communication system having an overlay network formed by participation of a plurality of node devices connected to each other via a communication path,

One node device included in the plurality of node devices is:

Storage means for storing node information indicating a node device that is a candidate for an information transfer destination; and a participation request information that indicates a participation request to the overlay network and includes the node information of the node device that requests participation In this case, it is determined whether or not the node information indicating the transfer destination node device according to the node information of the participation request node device is stored, and the node information indicating the transfer destination node device is stored. A participation request information transfer means for transferring the participation request information to the node device, and a node of the participation request node device that is the transmission source of the participation request information when the participation request information is received. Stores node information indicating a node device other than the transfer destination according to the information, determines whether or not it has power, and stores node information indicating a node device other than the transfer destination. If it is the the existence confirmation information transmission means for transmitting existence confirmation information including the node information of the participation request node device to the node device,

Reply information transmitting means for transmitting reply information to the participation request node device when the presence confirmation information is received;

An information communication system comprising:

[2] A communication method in an information communication system having an overlay network formed by participation of a plurality of node devices connected to each other via a communication path, the node device included in the plurality of node devices Storing node information indicating a node device that is a candidate for an information transfer destination; and

When receiving participation request information indicating a participation request to the overlay network and including participation request node information of the participation request node device, a transfer destination node device according to the node information of the participation request node device Determining whether or not the node information indicating is stored, storing the node information indicating the transfer destination node device, and transferring the participation request information to the node device,

When the participation request information is received, the participation request information transmission source is the participation request information. The node information indicating the node device other than the transfer destination according to the node information of the request-requesting node device is stored, and it is determined whether or not the power is stored, and the node information indicating the node device other than the transfer destination is stored. A step of transmitting presence confirmation information including node information of the participation request node device to the node device,

A step of transmitting reply information to the participation request node device when the presence confirmation information is received;

A communication method characterized by comprising:

[3] A node device included in an information communication system having an overlay network formed by participation of a plurality of node devices connected to each other via a communication path,

Storage means for storing node information indicating a node device that is a candidate for an information transfer destination; and a participation request information that indicates a participation request to the overlay network and includes the node information of the node device that requests participation In this case, it is determined whether or not the node information indicating the transfer destination node device according to the node information of the participation request node device is stored, and the node information indicating the transfer destination node device is stored. A participation request information transfer means for transferring the participation request information to the node device, and a node of the participation request node device that is the transmission source of the participation request information when the participation request information is received. The node information indicating the node device other than the transfer destination according to the information is stored, it is determined whether or not the power is stored, and the node information indicating the node device other than the transfer destination is stored. If it is the the existence confirmation information transmission means for transmitting existence confirmation information including the node information of the participation request node device to the node device,

A node device comprising:

[4] The node device that has received the reply information from the node device according to claim 3, and has storage means for storing the node information corresponding to the node device that is the transmission source of the received reply information. A node device characterized by the above.

[5] The node device according to claim 3, The storage means stores the node information and unique identification information corresponding to the node information in association with each area of the identification information,

The participation request information transfer means adds area specifying information specifying a predetermined area in the storage means to the participation request information when transferring the participation request information, and the presence confirmation information transmitting means receives If the node information of another node device as a transmission destination is stored according to whether or not the region designation information is added to the participation request information and the content of the region designation information, the node device The node device transmits the presence confirmation information to a node device.

[6] The node device according to claim 5,

The area of the identification information is divided into a plurality of areas according to the rules of the identification information, and until the area where only the own node apparatus belongs, the area to which the own node apparatus belongs follows the rules of the identification information. In addition, the presence confirmation information transmitting means stores the region designation information in the identification information, if the region designation information is added to the received participation request information. The existence confirmation information is transmitted to other node devices belonging to the area corresponding to

In the case where the area designation information is added to the received participation request information, the participation request information transfer means is an area corresponding to a range smaller than the area of the identification information corresponding to the area designation information. The node device is characterized in that the region designation information designating a node is added to the participation request information.

[7] The node device according to any one of claims 3, 5 and 6,

When the presence confirmation information is transmitted by the presence confirmation information transmission unit, the node further includes a node information transmission unit that transmits the node information of the node device that is the transmission destination of the presence confirmation information to the participation request node device. A node device characterized by the above.

[8] A recording medium in which an information processing program for causing a computer to function as the node device according to any one of claims 3 to 7 is recorded in a computer-readable manner.